History of Quinolones and Their Side Effects

Fluoroquinolone development from 1985 to the present was reviewed. Severe drug adverse events were noted for enoxacin, pefloxacin and fleroxacin, which were phototoxic. Temafloxacin was associated with severe hemolytic-uremic syndrome, lomefloxacin caused phototoxicity and central nervous system (CNS) effects, and sparfloxacin was associated with phototoxicity and QTc prolongation. Tosufloxacin caused severe thrombocytopenia and nephritis, and hepatotoxicity was reported for trovafloxacin. Grepafloxacin was withdrawn due to cardiovascular effects, and clinafloxacin was associated with phototoxicity and hypoglycaemia. The structure of the quinolones directly relates to both their activity and side-effect profiles. The relationship among specific substituents attached to the quinolone nucleus are clarified. The incidence of specific adverse events associated with individual fluoroquinolones was reviewed in a five-year post-marketing surveillance (PMS) study in Japan, in which a total adverse drug reaction (ADR) rate of 1.3% was found for levofloxacin, compared to total ADR rates of 3.3% for pazufloxacin, 3.6% for tosufloxacin, 4.5% for gatifloxacin and 5.4% for balofloxacin. Gastrointestinal effects were the most common adverse events for all fluoroquinolones. Levofloxacin had the lowest rate of CNS effects and skin adverse events among the agents listed.